I tried to gather information about the difference between Emulator and Simulator terms. Now the difference is more clear.

In computer science both a simulation and emulation produce the same outputs, from the same inputs, that the original system does; However, an emulation also uses the same processes to achieve it and is made out of the same materials. A simulation uses different processes from the original system. Also worth noting is the term replication, which is the intermediate of the two – using the same processes but being made out of a different material.

See table below:

Emulation / Emulator Simulation / Simulator Imitation / Imitator
An emulation is a model of some system that captures the functional connections between inputs and outputs of the system, based on processes that are the same as, or similar to, those of that system, and that is built of the same materials as that system. A simulation is a model of a system that captures the functional connections between inputs and outputs of the system, but without necessarily being based on processes that are the same as, or similar to, those of the system itself. A replication is a model of a system that captures the functional connections between inputs and outputs of the system and is based on processes that are the same as, or similar to, those of the system itself.
The microprogram-assisted macroprogram which allows a computer to run programs written for another computer. One that simulates, especially an apparatus that generates test conditions approximating actual or operational conditions. Something derived or copied from an original.
Hardware, software or a combination of the two that enables a computer to act like another computer and run applications written for that computer. In the past, it was often a hardware add-on that actually contained an instruction execution module for the emulated computer. Today, “emulator” more often refers to software, which provides a translation layer from the emulated computer to the computer it is running in. The emulator may translate machine language, calls to the operating system or both.
An emulator in computing duplicates (provides an emulation of) the functions of one system using a different system, so that the second system behaves like (and appears to be) the first system. This focus on exact reproduction of external behavior is in contrast to some other forms of computer simulation, which can concern an abstract model of the system being simulated.
A broad collection of methods used to study and analyze the behavior and performance of actual or theoretical systems. Simulation studies are performed, not on the real-world system, but on a (usually computer-based) model of the system created for the purpose of studying certain system dynamics and characteristics. The purpose of any model is to enable its users to draw conclusions about the real system by studying and analyzing the model. The major reasons for developing a model, as opposed to analyzing the real system, include economics, unavailability of a “real” system, and the goal of achieving a deeper understanding of the relationships between the elements of the system.
Simulation can be used in task or situational training areas in order to allow humans to anticipate certain situations and be able to react properly; decision-making environments to test and select alternatives based on some criteria; scientific research contexts to analyze and interpret data; and understanding and behavior prediction of natural systems, such as in studies of stellar evolution or atmospheric conditions.

With simulation a decision maker can try out new designs, layouts, software programs, and systems before committing resources to their acquisition or implementation; test why certain phenomena occur in the operations of the system under consideration; compress and expand time; gain insight about which variables are most important to performance and how these variables interact; identify bottlenecks in material, information, and product flow; better understand how the system really operates (as opposed to how everyone thinks it operates); and compare alternatives and reduce the risks of decisions.
Someone who copies the words or behavior of another; Someone who (fraudulently) assumes the appearance of another.
Emulation is the process of mimicing the outwardly observable behavior to match an existing target. The internal state of the emulation mechanism does not have to accurately reflect the internal state of the target which it is emulating.
The goal of an emulation is to able to substitute for the object it is emulating.
Simulation involves modeling the underlying state of the target. The end result of a good simulation is that the simulation model will emulate the target which it is simulating.
A simulation’s focus is more on the modelling of the internal state of the target — and the simulation does not necessarily lead to emulation. In particular, a simulation may run far slower than real time.

Simulator and Emulator both run in same environment, but in different ways. Simulator is an application that simulates similar environment to the original device's OS, but does not work over the real operating system. On the other hand, Emulator is a software that works by duplicating every aspect of the original device's behavior.